All athletes seek a competitive advantage through training on high altitude areas such as Iten, Kenya. Although the benefits of some interventions in this training conditions are clear, most strategies are less well proven. Altitude is no exception to this. Training at high altitude has been used by competitive athletes as a means of improving their potential. However, despite a good deal of research into the topic, its true effects and a recommended approach are still not well established. Additionally, altitude training is usually expensive and fraught with logistical problems.
Benefits of Altitude Exposure
Exposure to high altitude could theoretically improve an athlete’s capacity to exercise. Exposing the body to high altitude causes it to acclimatise to the lower level of oxygen available in the atmosphere. Many of the changes that occur with acclimatisation improve the delivery of oxygen to the muscles -the theory being that more oxygen will lead to better performance.For any type of exercise lasting longer than a few minutes, the body must use oxygen to generate energy. Without it, muscles simply seize up and can become damaged. This type of exercise is called aerobic exercise, meaning with oxygen.
The body naturally produces a hormone called erythropoetin (EPO) which stimulates the production of red blood cells which carry oxygen to the muscles. Up to a point, the more blood cells you have, the more oxygen you can deliver to your muscles. There are also a number of other changes that happen during acclimatisation which may help athletic performance, including an increase in the number of small blood vessels, an increase in buffering capacity (ability to manage the build up of waste acid) and changes in the microscopic structure and function of the muscles themselves.
Problems of Altitude Exposure
However, acclimatisation to high altitude is not simple, and there are a number of other effects that could cancel out the above benefits. For example the increase in red blood cells comes at a cost - having too many blood cells makes the blood thicker and can make blood flow sluggish. This makes it harder for your heart to pump round the body, and can actually decrease the amount of oxygen getting to where it is needed.At very high altitudes (>5000m), weight loss is unavoidable because your body actually consumes your muscles in order to provide energy. There is even a risk that the body’s immune system will become weakened, leading to an increased risk of infections, and there may be adverse changes in the chemical make-up of the muscles. Additionally, the body cannot exercise as intensely at altitude. This results in reduced training intensity, which can reduce performance in some sports. At very high altitudes, further problems are encountered: loss of appetite, inhibition of muscle repair processes and excessive work of breathing. On top of this, there is the problem of altitude illnesses, which can dramatically reduce the capacity to be active at altitude, or foreshorten the exposure to high altitude altogether.
ReplyDeleteAltitude Sickness
Every year, people die of altitude sickness. All of these deaths are preventable. If you are traveling above 2500m (8000ft), read this information and tell your companions about it - it could save your life.
What is altitude sickness?
Altitude sickness has three forms. Mild altitude sickness is called acute mountain sickness (AMS) and is quite similar to a hangover - it causes headache, nausea, and fatigue. This is very common: some people are only slightly affected, others feel awful. However, if you have AMS, you should take this as a warning sign that you are at risk of the serious forms of altitude sickness: HAPE and HACE*. Both HAPE and HACE can be fatal within hours.
HAPE
HAPE is excess fluid on the lungs, and causes breathlessness. It is never normal to feel breathless when you are resting - even on the summit of Everest. This should be taken as a sign that you have HAPE and may die soon. HAPE can also cause a fever (a high temperature) and coughing up frothy spit. HAPE and HACE often occur together.
HACE is fluid on the brain. It causes confusion, clumsiness, and stumbling. The first signs may be uncharacteristic behaviour such as laziness, excessive emotion or violence. Drowsiness and loss of consciousness occur shortly before death.
Treatment of HAPE and HACE
Immediate descent is absolutely essential
Dexamethasone and acetazolamide should both be given, if available
Pressure bags and oxygen gas can buy time
What causes altitude sickness?
Two things are certain to make altitude sickness very likely - ascending faster than 500m per day, and exercising vigourously. Physically fit individuals are not protected - even Olympic athletes get altitude sickness. Altitude sickness happens because there is less oxygen in the air that you breathe at high altitudes.
Altitude sickness prevention
Go up slowly, take it easy, and give your body time to get used to the altitude. The body has an amazing ability to acclimatise to altitude, but it needs time. For instance, it takes about a week to adapt to an altitude of 5000m.